1 files changed, 163 insertions, 0 deletions
diff --git a/hw/s390x/tod-kvm.c b/hw/s390x/tod-kvm.c
new file mode 100644
index 000000000..ec855811a
--- /dev/null
+++ b/hw/s390x/tod-kvm.c
@@ -0,0 +1,163 @@
+/*
+ * TOD (Time Of Day) clock - KVM implementation
+ *
+ * Copyright 2018 Red Hat, Inc.
+ * Author(s): David Hildenbrand <david@redhat.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ */
+
+#include "qemu/osdep.h"
+#include "qapi/error.h"
+#include "qemu/module.h"
+#include "sysemu/runstate.h"
+#include "hw/s390x/tod.h"
+#include "kvm/kvm_s390x.h"
+
+static void kvm_s390_get_tod_raw(S390TOD *tod, Error **errp)
+{
+    int r;
+
+    r = kvm_s390_get_clock_ext(&tod->high, &tod->low);
+    if (r == -ENXIO) {
+        r = kvm_s390_get_clock(&tod->high, &tod->low);
+    }
+    if (r) {
+        error_setg(errp, "Unable to get KVM guest TOD clock: %s",
+                   strerror(-r));
+    }
+}
+
+static void kvm_s390_tod_get(const S390TODState *td, S390TOD *tod, Error **errp)
+{
+    if (td->stopped) {
+        *tod = td->base;
+        return;
+    }
+
+    kvm_s390_get_tod_raw(tod, errp);
+}
+
+static void kvm_s390_set_tod_raw(const S390TOD *tod, Error **errp)
+{
+    int r;
+
+    r = kvm_s390_set_clock_ext(tod->high, tod->low);
+    if (r == -ENXIO) {
+        r = kvm_s390_set_clock(tod->high, tod->low);
+    }
+    if (r) {
+        error_setg(errp, "Unable to set KVM guest TOD clock: %s",
+                   strerror(-r));
+    }
+}
+
+static void kvm_s390_tod_set(S390TODState *td, const S390TOD *tod, Error **errp)
+{
+    Error *local_err = NULL;
+
+    /*
+     * Somebody (e.g. migration) set the TOD. We'll store it into KVM to
+     * properly detect errors now but take a look at the runstate to decide
+     * whether really to keep the tod running. E.g. during migration, this
+     * is the point where we want to stop the initially running TOD to fire
+     * it back up when actually starting the migrated guest.
+     */
+    kvm_s390_set_tod_raw(tod, &local_err);
+    if (local_err) {
+        error_propagate(errp, local_err);
+        return;
+    }
+
+    if (runstate_is_running()) {
+        td->stopped = false;
+    } else {
+        td->stopped = true;
+        td->base = *tod;
+    }
+}
+
+static void kvm_s390_tod_vm_state_change(void *opaque, bool running,
+                                         RunState state)
+{
+    S390TODState *td = opaque;
+    Error *local_err = NULL;
+
+    if (running && td->stopped) {
+        /* Set the old TOD when running the VM - start the TOD clock. */
+        kvm_s390_set_tod_raw(&td->base, &local_err);
+        if (local_err) {
+            warn_report_err(local_err);
+        }
+        /* Treat errors like the TOD was running all the time. */
+        td->stopped = false;
+    } else if (!running && !td->stopped) {
+        /* Store the TOD when stopping the VM - stop the TOD clock. */
+        kvm_s390_get_tod_raw(&td->base, &local_err);
+        if (local_err) {
+            /* Keep the TOD running in case we could not back it up. */
+            warn_report_err(local_err);
+        } else {
+            td->stopped = true;
+        }
+    }
+}
+
+static void kvm_s390_tod_realize(DeviceState *dev, Error **errp)
+{
+    S390TODState *td = S390_TOD(dev);
+    S390TODClass *tdc = S390_TOD_GET_CLASS(td);
+    Error *local_err = NULL;
+
+    tdc->parent_realize(dev, &local_err);
+    if (local_err) {
+        error_propagate(errp, local_err);
+        return;
+    }
+
+    /*
+     * We need to know when the VM gets started/stopped to start/stop the TOD.
+     * As we can never have more than one TOD instance (and that will never be
+     * removed), registering here and never unregistering is good enough.
+     */
+    qemu_add_vm_change_state_handler(kvm_s390_tod_vm_state_change, td);
+}
+
+static void kvm_s390_tod_class_init(ObjectClass *oc, void *data)
+{
+    S390TODClass *tdc = S390_TOD_CLASS(oc);
+
+    device_class_set_parent_realize(DEVICE_CLASS(oc), kvm_s390_tod_realize,
+                                    &tdc->parent_realize);
+    tdc->get = kvm_s390_tod_get;
+    tdc->set = kvm_s390_tod_set;
+}
+
+static void kvm_s390_tod_init(Object *obj)
+{
+    S390TODState *td = S390_TOD(obj);
+
+    /*
+     * The TOD is initially running (value stored in KVM). Avoid needless
+     * loading/storing of the TOD when starting a simple VM, so let it
+     * run although the (never started) VM is stopped. For migration, we
+     * will properly set the TOD later.
+     */
+    td->stopped = false;
+}
+
+static TypeInfo kvm_s390_tod_info = {
+    .name = TYPE_KVM_S390_TOD,
+    .parent = TYPE_S390_TOD,
+    .instance_size = sizeof(S390TODState),
+    .instance_init = kvm_s390_tod_init,
+    .class_init = kvm_s390_tod_class_init,
+    .class_size = sizeof(S390TODClass),
+};
+
+static void register_types(void)
+{
+    type_register_static(&kvm_s390_tod_info);
+}
+type_init(register_types);